Seals for gyratory crusher shafts



United States Patent SEALS FOR GYRATORY CRUSHER SHAFTS George D. Becker,Wauwatosa, Wis., assiguor to Nordberg Manufacturing Company, Milwaukee,Wis., a corporation of Wisconsin Application May 14, 1957, Serial No.659,134

Claims. (Cl. 308-142) My invention relates to an improvement insupporting means for the crushing head of a gyratory crusher, and hasfor one purpose to provide an improved oil seal for the upper orsuspended end of a gyratory crusher shaft.

Another purpose is to provide an oil seal applicable to the gyratorycrusher spider from which the upper end of the shaft of a gyratorycrusher is suspended.

Another purpose is to provide means for positioning such a seal as closeas possible to the fulcrum point, or the point about which the upper endof the crusher shaft gyrates during the normal operation of the crusher.

Another purpose is to provide such a seal which is accessible forreplacement and repair. Another purpose is to provide such a seal ofmaximum simplicity of structure coupled with efficiency of operation.

Another purpose is to provide such a seal in which any pumping orbuilding up of oil pressures is avoided.

Other purposes will appear from time to time in the course of thespecification and claims.

I illustrate my invention more or less diagrammatically in theaccompanying drawings, wherein:

Figure 1 is a vertical axial section through a complete sy y;

Figure 2 is a partial vertical axial section, on a considerably largerscale; and

Figure 3 is a partial vertical axial section of a seal, on a stilllarger scale.

Like parts are indicated by like symbols throughout the specificationand drawings.

Referring to the drawings, 1 generally indicates any suitable supportingbase upon which a main frame structure 2 is mounted. The structure 2 mayinclude an outer circumferential frame member 3, horizontally extendingconnecting webs 4, a central fixed bearing hub 5, and a bearing assemblyor sleeve 6 in which a suitable drive shaft 7 is positioned. This driveshaft may be driven by any suitable pulley 8, by belts or the like, froma source of power not herein shown.

The shaft is shown as having an inner pinion 9 in mesh with a bevel gear10 connected to and driving an eccentrically apertured sleeve 11 in saidhub. 12 indicates an upwardly and outwardly extending frame portion orbowl in which any suitable liner or liners 13 are positioned. 14 is atop spider assembly which may be centered in and secured to the bowl 12,as by bolts 15. The spider assembly supports an inner hub 16, having abore 17 of lesser diameter, and an upward extension of such bore 18 ofgreater diameter. As will be clear from Figure 1, a ledge 23 is a shaftsuspension sleeve, suitably secured to the upper end of the shaftportion 22 and extending outwardly above the ledge or shelf portion 19a.24 is a suspension ring mounted on the shelf portion 19a and secured inposition, for example, by suitable positioning pins 25 which are held insuitable apertures in the ledge 19 and extend into appropriate andsomewhat larger cylindrical apertures 26 in the suspension ring 24. 28is a suitable spider bushing, resting on the shelf portion 19. It willbe understood that sufficient clearance is provided at 17 to permit theshaft portion 22 to tilt slightly about its fulcrum or point of gyrationX. As will be clear from Figure 2, the shaft suspension sleeve 23surrounds and engages the crusher shaft 20. As the crusher shaft 20gyrates about its point of gyration X the suspension sleeve 23 moveswith it. In Figure 2 the lower surface of the suspension sleeve 23 istilted upwardly away from the upper surface of the suspension ring 24.It will be understood, of course, that at other positions of the shaftthe lower surface of the suspension sleeve abuts the upper surface ofthe suspension ring and the cylindrical outer surface of the suspensionsleeve may also abut the opposed inner surface of the spider bushing 28.In other words, as the shaft 20 gyrates, an area of contact between thesuspension sleeve 23 and the suspension ring 24 moves circumferentiallyabout the ring 24. Figure 2 is to be taken as diagrammatic rather thanas a working drawing, as the clearances have been indicated rather thanaccurately represented. The parts are so formed and proportioned as topermit such a slight gyration to take place, which, of course, isnecessary, since the crushing action is imparted to the head by rotatingthe drive shaft 7 and the eccentrically apertured sleeve 11. Thisrotation moves the lower end or portion 21 of the crusher shaft in agenerally circular path, to approach a suitable crushing head 29 anditsrmantle 30 to the opposed bowl 12 and the bowl liners 13. A problemsolved by the present structure is the provision of adequate oil sealingmeans for the spider of the gyratory crusher.

Considering, specifically, the sealing means employed, I show an oilseal retainer ring 31 which rests slidably upon the upper surface of thehorizontal shelf portion 19a. The suspension ring 24, upon which thesuspension sleeve 23 of the crusher shaft assembly rests, is providedwith a circumferential inner, lower recess 32. This recess has an upperhorizontal face 32a, an inner cylindrical face 32b, and a connectingfillet 32c. The oil seal retainer ring 31 is received snugly in therecess. The oil seal retainer ring 31, in turn, has an innercircumferential channel 35 in its inner cylindrical wall, in which ispositioned an O-ring 36.- The O-ring is under compression between theinner wall of the channel and the opposite outer wall of the crushershaft portion 22. The parts are so proportioned that, at all times, theO-ring 36 is under pressure and efficiently operates as a sealing memberto prevent any undesired escape or flow of lubricant downwardly alongthe outer surface of the crusher shaft. The

oil seal retainer ring 31 has in its lower surface an additionalcircumferential recess 37 which houses a second O-ring 38. It will benoted that the opposite walls or surfaces of the recess or channel 37incline toward each other and are so shaped and proportioned that theywill prevent the escape or loss of the O-ring 38, even when the sealingassembly is lifted upward from the shelf or ledge 19a.

In order to prevent any oil pumping action I provide a system ofchannels or vents or grooves in the various parts involved. Iillustrate, for example, a wide groove in the spider wall, shown at 40.It extends downwardly a sufficient distance to communicate with a radialgroove 41. Internal radial passages are also indicated, as at 43 in thesuspension ring 24. A circumferential outer groove,

as at 44, in the suspension ring, connects with a vertical extensionpassage 45. Thus, any tendency for building up of pressures or pumpingof oil is prevented, it being understood that any suitable arrangementor combination of grooves and vents may be employed. Those herein shownhave turned out to be practical.

It will be realized that, whereas, I have described and illustrated apractical and operative device, nevertheless many changes may be made inthe size, shape, number and disposition of parts without departing fromthe spirit of my invention. I therefore wish my description and drawingsto be taken as in a broad sense illustrative or diagrammatic, ratherthan as limiting me to myprecise showing. The use and operation of myinvention are as follows:

I show herein a gyratory crusher which consists of an outercircumferentially extending bowl shown, for example, at 12, and agyrated conic head, shown, for example, at 29. This head is mechanicallygyrated or rolled against rock or ore which is fed downwardly from aboveinto the crushing cavity defined by the head and bowl. As the eccentric11 is rotated by the rotation of the shaft 7 the. head is gyrated andopposes, in succession, a zone of nip or close approach, which movesaround the crushing cavity.

The shaft assembly, including the conic head, is suspended in the abovedescribed spider bearing. The suspension is actually obtained by theemployment of a flat supporting washer or suspension ring 24, whichrests on the ledge 19a and which receives, on its upper surface, thelower face of the slightly beveled suspension sleeve 23. The beveling ofthe lower surface of the suspension sleeve 23 is clearly shown in Figure2. The parts being thus shaped, there is always a level spot or area incontact with the supporting washer or ring 24. The suspension sleeve 23is held in position on the shaft in any suitable manner, for example, bythe threaded nut 46. It thus supports the head and shaft and takes thereaction due to the crushing of rock or ore in the crushing cavity.

, Since very heavy thrust is received in a relatively limited area, itisimportant that proper lubrication be maintained. In earlier crushermodels an upper bearing has been lubricated with oil, which had to bereplenished frequently, there being no means to contain oil in thehearing. The present invention is directed to providing an efficient andsimple sealing means to prevent the loss of lubricant. The suspensionring 24 and theoil seal retainer ring 31, in effect, divide theuniversal motion of the shaft 22 into a vertical sliding motion and ahorizontal sliding motion. The turning motion can divide itself equallybetween the two O-rings 36 and 38. In practice, the oil seal retainerring 31 is so proportioned as to fit snugly in the aperture or bore 32.Its dimension from the O-ring 38 in the bottom to its smooth upperbearing surface is slightly greater than the corresponding distance inthe cavity provided for the ring. This keeps the bottom O-ring 38slightly flattened so that it has a high unit bearing pressure. The

oil seal ring herein is further provided with a plurality of tap holes47 in its upper surface. Thus, after the operator has removed the partsabove the ring he can reach down into the bearing cavity with a properlyformed rod or tool and attach the rods to the ring 31 by means of thetap holes, and easily remove it for replacement or repair.

In the present structure the replacement and repair from above of thespider bearing and oil seal structure is possible without completelydismantling the upper portion of the crusher. The suspension sleeve 23,the suspension ring 24, and the spider bushing 28 may be upwardlyremoved, giving the operator access to the entire supporting and sealingstructure. This can be done without disassembling or removing thecrusher shaft.

Since the rolling action of the bearing bushings might act as aviscosity pump, if not vented, I employ, for example, the system ofvents and grooves shown at 40, 41, 43 and 44. This vent system preventsbuilding up of oil pressure and pumping.

I claim:

1. In a gyratory crusher having a suspended crusher shaft and head and aspider for suspending said shaft, said spider having a hub with anaperture through which the upper end of the crusher shaft may pass, anda generally horizontal ledge formed in saidaperture, the shaft having asuspension sleeve at its upper end, supporting and sealing means forsaid shaft and head including a suspension ring in said aperture, havinga lower surface engaging said ledge and an upper surface formed andpositioned to receive the opposed lower surface of the shaft suspensionsleeve, and sealing means for preventing the escape of oil downwardlyalong the surface of the crusher shaft and inwardly across the surfaceof the ledge, said sealing means including an oil seal retainer ringslidably supported on the surface of said ledge for movement in ahorizontal plane generally perpendicular to the axis of the crushershaft, and surrounding the outer surface of the crusher shaft, -.-saidretainer ring having a circumferential channel formed in its lowersurface and another in its inner surface, and seal rings in each saidchannel formed and adapted to be constantly compressed respectivelyagainst the upper surface fo the ledge and the outer surface ofv thecrusher shaft, said retainer ring being free to slide on the surface ofsaid ledge.

2. The structure of claim 1 characterized in that the retainer ring hasapertures in its upper surface formed and adapted to receive a liftingtool, whereby the ring. may be upwardly lifted from its seat, thechannel in its lower surface being undercut, whereby to prevent theundesired escape of the seal ring when the bottom of the retainer ringis out of contact with the ledge.

3. The structure of claim 1 characterized in that the suspension ring isrecessed about its lower inner edge snugly to receive the retainer ring.

4. The structure of claim 1 characterized in that the suspension ring isapertured to permit the passage of lubricant therethrough and by theprovision of vents in communication with said apertures, whereby oilpumping in response to the gyration of the crusher shaft is prevented.

5. The structure of claim 1 characterized in that the retainer ring islocated adjacent the level of the center of gyration of the crushershaft, whereby amplitude of lateral movement of the crusher shaft at itszone of opposition to the retainer ring is reduced to a minimum.

References Cited in the file of this patent UNITED STATES PATENTS557,216 McCully Mar. 31, 1896 2,492,006 Raybould Dec. 20, 1949 2,678,837Griefen May 18, 1954

